Electrical connector frame construction



Feb. 7, 1967 D, 1. CROWLEY ETAL 3,303,454

ELECTRICAL CONNECTOR FRAME CONSTRUCTION Filed July 2, 1964 6 Sheets-Sheet l 6 Sheets-Sheet 2 D. .lp CROWLEY ETAL ELECTRICAL CONNECTOR FRAME CONSTRUCTION YR E u. o M w M 0 m 5 7 .l 4 a| L 2 \.C v 4| 4 ,L a N E NME. .EIIEV llr f A s CII- [EO Irllll N O F F OO O [L O O 0000 0 7 O 0 0 L O EL. O O l. MR 0 0 o A m 5 5 6 d 0 0 0 II' -L 0 *IIIILL D 00 0 o 0 0 0 0 0 .o 0 0 0 4| 0 00 0 0 0 0 o 0 o 0 0 0 0 0 00 d 0 0 0 F 00 2 o o n o e .F n 0 00 0 0 o o 0 0 o 0 0000 00 O O 0 00 0 00 0000 0 00 00 0 00m o 00 0 0 XUOQ f F O\f :l -F d Feb. 7, 1967 Filed July 2, 11.964

Feb. 7, 1967 D. J, CROWLEY ETAL 3,303,454

ELECTRICAL CONNECTOR FRAME CONSTRUCTION Filed July 5J, l964 6 Sheets-Sheet 3 O C2 o 0 0 A o OOO 000 000 O 0 00000000 OOO 00 o0 0 o0 00 0 o 0000 00 o 0000 o 0 00 0 0 000 0 0 o o 0 0 0 o 0 0 000 000000 oo 0 0000 x o0 .1v l Y N l xfs 2 b NVENTURS :DANIEL Josiwn CRewL my CHARLEs "Romein" SANUER- www, wmf/M Feb. 7, 1967 D. J. CROWLEY ETAL 3,303,454

ELECTRICAL CONNECTOR FRAME CONSTRUCTION Filed July 2, 1964 6 Sheets-Sheet 4 1\"v VfN'f/' :DANiEL JossPH CRowLsY CHARLES RoERT SANDERs Feb. 7, 1967 D. 1. CROWLEY ETAL l3,303,454

ELECTRICAL CONNECTOR FRAME CONSTRUCTION Filed July 2, 1964 6 Sheets-Sheet 5 NVENTORS DANsEL csh-PH CRowLuY CHARLES 'Roi'.wr immuun;

Feb. 7, 1967 D. J. CROWLEY ETAL 3,303,454

ELECTRICAL CONNECTOR FRAME CONSTRUCTION Filed July 2, 1964 6 Sheets-Sheet 6 INVENTORS :DANIEL osaPH Ccwnay CHARLES Ramnm' SAuues United States Patent C) 3,303,454 ELECTRICAL CONNECTQR FRAME CONSTRUCTION Daniel Joseph Crowley, Steeiton, and Charles R. Sanders,

Harrisburg, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed July 2, 1964, Ser. No. 379,995 6 Claims. (Cl. 339-18) This invention relates to an improved frame construction of the type used in plugboard devices or other electrical contact-carrying equipment.

In U.S. patent application, Serial No. 350,450, tiled March 9, 1964, in the name of Bruce R. McFadden et al., there is described a plngboard device construction and method wherein as a feature of the invention, it is tau-ght to employ a metallic frame having insulating board members secured therein by epoxy or similar plastic bonding material.

The device described in the McFadden et al. application has proven to be quite acceptable in providing a stronger, y

lighter and less expensive approach to plugboard construction as compared with prior art devices. The present invention is based in part upon the technique developed in the McFadden et al.application and constitutes an improvement thereover, having as one of its objectives the provision of an even better quality joining of insulating board members and metallic frame members of plugboard devices. It is a further object to provide a novel electrical equipment frame and insulating board construction which is stronger and better in appearance than heretofore available.

It is another object Vto provide a novel means and method 'for locking panel members within frame members by use of epoxy or similar bonding material in a manner whereby critical tolerances are avoided and assembly is facilitated.

It is yet another object to provide a novel means and method for multi-partl structureswhich produces a mechanical link of metallic and insulating materials used for panel construction of plugboard connector assemblies, or the like.

It is a .general object of the invention to provide an improved multiple electrical contact assembly construction and method of construction adaptable for both cast and extruded frame members in a use with contact-carrying boards.

Other objects land attainments of the present invention will 'become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there are shown and described illustrative embodiments of the invention; it is to be understood, however, that these embodiments are not intended to be exhaustive nor limiting of the invention, but are given for .purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

The foregoing objectives are obtained in the present invention through the use of a metallic frame member shaped to receive an insulating board member with the parts so sized in width dimension that a space isleft between the edges of such members; such space being lled with an epoxy or other exceptionally strong bonding material operating to resist parting of the components of the metallic or insulating board parts is made to provide 'interlocking surfaces with amounts of the bonding material operating to resist parting of the components of the structure. As a further feature, the shaping of such 3,363,454 Patented Feb. 7, 1967 parts is made to automatically facilitate deposits of the bonding material less than and more than the optimum amount with the appearance of the structure being enhanced by avoiding splash and uneven loading of the boudin-g material. A novel method of filler application is also contemplated as part of the invention. The foregoing features have been yfound to be substantial in providing a multiple electrical contact assembly having insulating panels and a separate frame which is both more rugged and less expensive than devices heretofore available.

In the drawings:

FIGURE 1 is a perspective of a :plugboard device including the front bay construction which lends itself to the advantages of the invention;

FIGURE 2A is a view of the front bay or control panel of the device shown in FIGURE l;

FIGURE 2B is a view of an alternative embodiment of the panel of the invention;

FIGURE 3 is a section taken along lines 3-3 of FIG- URE 2A showing in detail an aspect of the invention;

FIGURE 4 is a section similar to that shown in FIG- URE 3 but prior to assembly of the panel and frame of the control panel shown in FIGURE 2A;

FIGURE 5 is a section taken along lines 5-5 of FIGURE 2A;

FIGURE 6 is a section taken along lines 6 6 of FIGURE 2A;

FIGURE 7 is a section taken along lines 7-7 of lFIGURE 2A;

FIGURE 8 is a section similar to that of FIGURE 6 but of an alternative embodiment of frame construction and method of bonding a control panel to a frame; l FIGURE 9 is a section through a view of a plugboard substantially identical in function to that shown in FIG- URE 2A but with an alternative feature of frame construction and method of bonding for the frame shown in FIGURE 8; j

FIGURE 10 is a section similar to that shown in FIG- URE 7 but of yet a further embodiment of the invention featuring an alternative technique of locking an insulating panel to a frame member;

FIGURE 11 is a section similar to that shown in FIGURE 7 but of yet a further embodiment including a feature of the invention adapted to improve the appearance and reduce the cost of the construction of the assembly of the invention;

FIGURES 12 and 13 are sections similar to FIGURE 7 but of yet further embodiments of the frame of the invention having an improved locking feature; and

FIGURES 14-16 are gures depicting a preferred method of assembly useful with the embodiments of FIG- URES 1-13.

Referring tirst to FIGURE 1 the plugboard system there shown as I0 includes generally a rear bay 12 which houses a matrix of ilexible contact springs shown as 14 connected on the back side of the bay to leads which go to electrical components to be interconnected in various patterns in aC- cordance with a desired program. The bay 12 includes affixed to the bottom thereof a camming mechanism 16 having a cam or cams shown as 18 positioned to be driven by the operation of a handle 20 in an arcuate movement to engage the bottom of a front bay or control panel 40 when it is in the closed position. The control panel 40 is in FIGURE 1 shown in the open position and is in closure swung downwardly into the face of the rear bay 12 to rest upon and above cam 18 and to be driven thereby upwardly so that the patchcord pins shown as 34 extending on the front side of the bay engage springs 14 to eEect selected closures of the component paths. The control panel 40 has a series of support and anchoring pin members such as 28 near the top thereof adapted to lit within complementary slots not shown but generally as indicated by numeral 22 at the top of the rear bay and lower pin members such as 30 shown at the bottom of panel 40 adapted to cooperate with a locking latch mechanism in the rear bay. The panel 40 is comprised of a metallic frame shown as 44 housing a series of insulating boards 32 which, in turn, are apertured as at 37 to receive and secure the patchcords 34. By reason of handles 36, the panel 40 may be manipulated into and out of the rear bay for interchangeability of a patch program. Reference may be had to the above-mentioned McFadden et al. application for a more detailed description of the operation of the contact parts of the system.

As a general problem with systems of the type shown as thespring members 14 and the pin portions of patchcords 34 must be maintained in a rather exact alignment for proper operation. If for some reason misalignment occurs in construction or in use then the device will either fail by reason of developing an open circuit or by reason of an improper wipe of the contact surfaces which is important to plugboard system operation in the presence of vibration or other adverse environment. For this reason, substantial care is taken in the production of the cornponents with extremely close tolerances being heldwith respect to the frames and board members of both the front panel and back bay. In use, for eachback bay there may be ten, twenty or iifty front panels which are preprogrammed to represent a given set of controls and which are at different times inserted in the rear bay. The problem, therefore, of holding close tolerances is quite critical with respect to front panels since there are more of them. The McFadden et al. invention as described in the abovementioned application represents an answer to the problem by providing a construction which may be manufactured with less critical tolerances but which nevertheless may be assembled in such a fashion that the iinal product will be properly dimensioned. As part of the McFadden et al. disclosure it is taught to utilize a plastic filler which serves to bond the frame and boards together and to resist the substantial forces which are developed during use. This resistance to ow is necessary because the control panel, in carrying one or several thousand contacts against one or several thousand springs at six to eight ounces, develops relatively high forces. These forces are concentrated in parts of the frame of the panel and could if the bonding material were resilient, soft or yielding, cause a creeping or flowing of the material to reduce the contact pressures and/or cause open circuits to occur. The epoxy mentioned in the McFadden et al. application has been found to be quite satisfactory for this use in that it has considerable compressive and tensile strength.

Referring now to FIGURE 2A and to the FIGURES 3-7 an analysis of forces acting on panel 4t) will be given as a brief prelude to a description of the advantages of the invention. Looking now to FIGURE 2A which represents a cast version of the control panel incorporating the invention, camming forces shown as F are applied to projection 42 of panel 40 to drive the panel upwardly and hold it against the forces of all of the patchboard pins and springs. The forces F are distributed to the panel frame 44 and then to the board members 32. The principal` part of the forces carried are compressive lbut with an unbalanced loading of the panel by patchcords being inserted on one side or ,the other, forces F are developed which develop couples in parts of the frame and boards tending to shear the boards from the frame and therefore placing tensile stresses on the bonding material between the panel and frame. In certain uses and with certain types of patchcord designs, forces F" develop tending to push the boards out of the frame in a sense transverse to the plane of the boards as shown in FIGURE 3. Such forces may combine with the forces F and F to further place the material between the board and frame in tension.

As an important aspect when the control panel 40 is loaded with a full program of patchcord leads, the weight of the patchcord leads is in excess of that of the panel and if the panel is placed face down as it usually is when removed from a rear bay, a substantial force is developed tending to break the boards out of the frame. In many instances, the use of the plugboard system is such that construction of the McFadden et al. patent application is more than adequate. In many applications, it is desirable to have a stronger bond between the board and frame members than has been heretofore possible.

As a second problem area developed by experience with prior art uses of epoxy and like materials to join board and frame members there is that which involves having excess or uneven epoxy material appearing at the edge of the board and frame. Thus, in prior art devices it is frequently the case that an examination of the frame reveals epoxy material splattered up on the side of the frame on the front side thereof or appearing uneven along the line of the members. Excess bonding material may not cause structural problems, Ialthough if allowed to run out onto the board face or into the apertures, it will, of course, effectively ruin the control panel by blocking the insertion of a patchcord. In standard construction, the edge row of apertures such as those shown by numeral 37'is approximately a fourth of an inch from the edge of the frame and a patchcord body extends out somewhat from the aperture. Thus, if the excess epoxy material is present on the surface of the board it may nevertheless-impede the insertion of the patchcord even though no aperture is actually blocked.

Aside fromstructunal shortcomings, the presence of excess bonding material on the frame or on the panel will, for appearanlce sake |alone, cause the panel to be unacceptable to customers and since the parts are bonded together, the entire assembly must be scrapped. Even with considerable care in assembly in wiping off any excess bonding material that may work out onto the edge of the frame or the board, it has been found that during curing when the assemblies are in an oven, excess bonding material may iiow on-to the surfaces and set in a state which can no longer be removed to, thus, in elect, ruin the assembly. The invention overcomes the immediately foregoing problem with a change in the configuration of the frame mernlber in one embodiment and with an improved method in another embodiment.

FIGURE 2B depicts an alternative version of a control panel construction which may incorporate the features hereinafter described relative to the cast version of FIG- URE 2A and particularly the features described relative to FIGURES 8, 9, 12 and 13. In FIGURE 2B, the members forming frame 44 are joined at the ends thereof by dowels, screws, yor the like, and the frame is identical in general configuration. To achieve the function of the projections, such as 42, separate metallic pads shown as 42 are added to the main frame members.

Turning now to FIGURE 3, there is shown an enlarged section of a portion of the frame 44 of panel 40 relative to Ia portion of a lboard 32. As can be seen the board 32 is nested within a recessed portion with the edge surface thereof opposite the transverse surface of the recess and spaced therefrom by a material 50 which has characteristics lof epoxy glue or cement to bond the board to the frame. The shape of the frame recess is such as to include a portion 46a, a portion 46b and a portion 46c; the latter portions being separated by a tiange 44a of frame 44. As can be seen from FIGURE 3, material 50 extends up to one surface lof 32 around the edge within portion 46b, across a section of the surface of 44a to iill portion 46c to form a bead which extends around the entire frame on the front side thereof.

In a preferred embodiment there is a slight angle given to the interior surface of 44 as shown in FIGURE 3. This angle shown as A results in there being a body of material 50 which is thicker progressively up the recess toward the back surface of board 32; i.e., the rear side of panel 40.

lslightly overiill the recess portion 46b and Work out onto thesurface of flange 44a. Typical bonding material before setting and at'roofm temperature may have a fluidity only slightly greater than lightweight oil. Because of this, vthe problem with running is accentuated. As the board 32 is bedded down within the frame recess portion 46a against the surface of 44a, the lower edge thereof contacts the ymaterial 50. Then with the Iboard held against the surface, the material 50, if slightly in excess, tends to ow by capillary action between the board surface-and the surface of 44a due to la slight space left by production disparities. The recess 46c operates to take up and hold such material'against running out onto the exposed surfaces of the board and frame by surface tension. Thereafter in one embodiment, the recess portion 1v46a may .be lled without lcausin-g flow through 46b over the surface of44a ,and out of recess portion 46c. As can be seen fromFIGURE 3, material 50 then extends around yTand between the board 32.

' FIGURES 8 and 9 show an alternative embodiment by sections of a frame y44' ofthe invention particularly radapted toAan extruded frame member of the type shown `in FIGURE 2B. With this embodiment, the innermost `portion shown as 46b is set in an angle relative. to the frame outer surface. The material shown as 50' thus then forms a lock against displacement of board 32 out of the frame.a.Withthis arrangement, av complete severance of bonding between Vthe material 50 and the frame surface can!l occur 'without 'the board 32 becoming loosened from the.frame...Depending upon the surface characteristics of the frame material the embodiments vof FIGURES V8.and9 maybe preferred. The embodiments of FIGURES 8 Iand 9 are particularly useful with frames made from extruding which'readily permit the type 0f olfset carried by 46b. The recess portions shown as 46b and 46c in conjunction with the flange 44a are included in this embodiment for the features and advantages described relative to FIGURES 3-7.

FIGURE lO shows still a further embodiment of the invention relative to frame 44 having a recess comprised of portions 46a, 46b and 46c as abovedescribed but having board member 32 which includes an edge 33 at an angle B with respect to the plane of board 32 which increases the volume or space between such edge Iand the edge of the frame 44. This permits a greater quantity of bonding material 50 to be employed and upon its being set and cured, the material forms a Wedge with the surface 33 locking the board 32' to the frame even if the bonding between board and material should fail.

FIGURE l1 shows a further alternative embodiment of the frame having the features above described with respect to the recess 46c which engage the outer surface of the board member and at the top having an additional width formed by recess 46d which operates to receive the material caused to How upwardly by insertion of the board member. In conjunction with this the scoring of the edge of the board as at 35 serves to establish at this surface a volume which will accommodate material 50 and serve to producea proper appearance.

FIGURE 12 shows still a further embodiment wherein down within the frame 44 there is established an additional volume for material shown as 47 which serves to lock the bonding material to the frame.

The foregoing embodiments drawn to the shaping of the recess 0f the frame member and/or of the board member are alternatives which may be preferred depending upon factors of cost, total reliability and materials employed. It should now be apparent to those skilled in the art which embodiment is best suited in view of these factors. As a general rule, if the frame member is of a relatively nonporous material, such as extruded aluminum, and the board material is -a molded phenolic resin, a material which is somewhat porous and which is quite compatible with epoxy cement then the likelihood of 'a separation is greater with respect to the frame member and, therefore, a locking feature of the type in FIGURES l2 -and 13 is preferred. If, on the other hand, the frame is of porous material or has a relatively :rough surface as such -as with certain types of cast metal members, a compromise for the sake -of economy will permit the use of embodiments of the type shown in FIGURES 3 and ll.

If the material used for the frame and the material used for the board are such as to be relatively nonporous so that any break of the bonding material is likely to occur in both, then the locking features of the embodiments of FIGURES l0 and l2 may need to be combined as in FIGURE 13. In this embodiment, the board 32" would have its edge 33 shaped in the manner shown with respect to FIGURE 10 and the frame would have a recess such as 49 so that even if the bonding material were t0 be completely separated from both surfaces the frame and the board would nevertheless be held together due to the body of material.

In conjunction with shaping of the frame and/ or board members and the use of a bonding material such as epoxy cement to bond the members together with provisions for'drawing and holding such material in its `proper place there is a further method which is part of the invention which will now be described with respect to FIGURES 14, 15 and 16. Referring to FIGURE 14, there is 'iucluded a frame 44 shaped as above-described in FIGURE 6 but loaded with bonding material '50 to an extent substantially less than indicated in FIGURE 3. The amount of material 50 placed inthe frame is approximately just enough to fill the recesses 46b" and 46c" when the b-oard 34 is properly positioned. This is indicated in FIGURE 15. In conjunction with the loading indicated in FIG- URE 14 and after the board 34 has been placed into position and centered by the technique described in the application to McFadden et al., it may then be held by the provisions of clamps and/or tie down screws locking the board 34 to the frame 44. This serves to eliminate board warp and further prevent epoxy flow. At this point the frame, suitably clamped, is placed in a heated atmosphere as in a commercial oven and raised to a temperature to speed the setting of the material 50. In the case of epoxy or similar materials as soon as the material 50 is set, it may then be -removed from the oven, the jig removed and the frame stacked for time curing. Either before the frames are stacked for time curing or at sometime during the curing as part of the invention an additional volume of epoxy material shown as S1 is preferably added to the extent shown in FIGURE 15. The material 51 is, of course, time set and cured. One advantage of this is that a given type of epoxy having a relatively fast setting time may be employed as a material 50 as shown in FIGURE 14 .and a different material, such as, 51 having a slower setting and curing time but having more stable characteristics may be employed as in FIGURE 16. Of course, and as is the present practice, the materials 50 and S1 may be the same and the Iprinciple advantage gained is by Ireducing the amount of time that the board need be kept in an oven and need be jigged. As a practical point, this serves to reduce the number of jig fixtures which are required for any production operation and, in essence, to reduce the amount of time that a given oven or heating fixture is occupied by frames. It desired, a number of pin members, such as 53 shown in phantom, may be inserted Within apertures formed in 34 and 44 prior to the addition of material 51 which will then set land cure about the pins to further lock the members together.

In an actual unit made in accordance with the practice of the article of the invention, an assembly of configuration of FIGURE 6 was constructed for a board 34 which was approximately 319/1000 inch in thickness having the edge surface roughened 'and with the space between the edge of the board and the frame approximately 6%000 inch with a l degree taper relative Ito the board edge, i.e., angle A. The recess 46b was approximately 9%000 inch maximum depth and 4%000 inch in width. The 4recess 46c was approximately 3%000 inch in depth and 5/%000 inch in width. The board was constructed of molded phenolic resin and the frame was `constructed of cast aluminum. The bonding material used was a commercial grade epoxy No. C94758 Resin and Hardener H2-3561 manufactured and supplied by Hysol Corporation of Olean, New York. The features described with respect to FIGURES 14-16 were practiced with a first quality of 50 as indicated in FIGURE 14 being loaded in the frame with the board 34 jigged therein and clamped and the entire unit placed in the heated oven at 140 degrees Fahrenheitia few degrees and held for 60 minutesia few minutes. Thereafter, the frame was removed from the oven, the clamps removed and the remainder of the recess filled with the same epoxy which was lef-t for a minimum of l2 hours for curing. The unit manufactured in accordance with the foregoing was found to be satisfactory in appearance and so well bonded together that attempts to obtain a release of the board from the frame resulted in a fracture of the board at a point apart from the joint formed by the epoxy compound.

What is -claimed is:

1. An assembly for electrical contactor panels and the like comprising at least one insulating board member having a mat-nix of transverse `apertures in the major surface thereof adapted to secure contactors inserted therein which are loaded under substantial forces, a frame surrounding and supporting said board, said frame including an interior recess having first, second and third portions substantially lilled with a fluid thermosetting plastic bonding material, the rst recess portion extending along the frame interior surface opposite the edge surface of said board and spaced therefrom substantially entirely around said board, the second recess portion extending below the surface of said boa-rd to define a reservoir for said material, the third recess portion being spaced from said second recessed portion by a flange of said frame which extends to supportsaid board whereby to limit flow of said uid material from said reservoir out onto the surface of said board.

2. The assembly of claim 1 wherein said first recess portion is defined by the surfaces of the edge of said board and the interior surface opposite therefof said frame, said surfaces being in intersecting planes to dene a taper therebetween.

3. The assembly of claim 2 wherein the edge surface of said board is substantially perpendicular to the 'major surface of said board.

4. The assembly of claim 2 wherein the edge surface of said board is at an acute angle with respect to the plane of a major surface of said board.

5. An assembly for electrical contactor panels of the type used in plugboard devices comprising a number of insulating board members each including a matrix of transverse apertures adapted to secure contactors inserted therein Which are loaded under substantial forces, `a frame surrounding and supporting said board members, said frame including an interiorrecess having first, second and third portions with the second and thirdr portions being spaced by a ange portion of `said frame and with the first and third portions being adjacent to outer surface areas of said frame, the Vsaidboardfbeing nested within the recess of said frame substantially 'against said frame flange and spaced from the interior surface of said frame through said first recess portion along at least two edges of a board member, the said recess portion being substantially filled with-an epoxy-like bonding material, the said ange and third recess portions yserving to hold said material when in its fluid state 'against running to strengthen thebonding of said board .to said frame after said bonding material h-as set andjcured onto the surfaces-of said board or said frame. 3

6. The assembly of claim 5 wherein the second recess portion extends transversely within said frame to define a volume of bonding material to mechanically lock the said material to the frame andthereby said board against displacement in said frame.

References Cited by the Examiner UNITED STATES PATENTS EDWARD C. ALLEN, Primary Examiner.,

PATRICK A. CLIFFORD, Examiner. 

1. AN ASSEMBLY FOR ELECTRICAL CONTACTOR PANELS AND THE LIKE COMPRISING AT LEAST ONE INSULATING BOARD MEMBER HAVING A MATRIX OF TRANSVERSE APERTURES IN THE MAJOR SURFACE THEREOF ADAPTED TO SECURE CONTACTORS INSERTED THEREIN WHICH ARE LOADED UNDER SUBSTANTIAL FORCES, A FRAME SURROUNDING AND SUPPORTING SAID BOARD, SAID FRAME INCLUDING AND INTERIOR RECESS HAVING FIRST, SECOND AND THIRD PORTIONS SUBSTANTIALLY FILLED WITH A FLUID THEREMOSETTING PLASTIC BONDING MATERIAL, THE FIRST RECESS PORTION EXTENDING ALONG THE FRAME INTERIOR SURFACE OPPOSITE THE EDGE SURFACE OF SAID BOARD AND SPACED THEREFROM SUBSTANTIALLY ENTIRELY AROUND SAID BOARD, THE SECOND RECESS PORTION EXTENDING BELOW THE SURFACE OF SAID BOARD TO DEFINE A RESERVOIR FOR SAID MATERIAL, THE THIRD RECESS PORTION BEING SPACED FROM SAID SECOND RECESSED PORTION BY A FLANGE OF SAID FRAME WHICH EXTENDS TO SUPPORT SAID BOARD WHEREBY TO LIMIT FLOW OF SAID FLUID MATERIAL FROM SAID RESERVOIR OUT ONTO THE SURFACE OF SAID BOARD. 